We meet early on a crisp Saturday morning in the gardens of the Chester Beatty Library in Dublin; a place, he later tells our tour group of 10, that offered him refuge when he himself spent some time without a place to call home.

“I used to come in here and draw,” he explains. “The lockers were €1 a go so I could come in and leave my stuff here. After a while they got to know me, so they would forgo the payment. They were very kind to me.”

The Dubliner is the first employee of Secret Street Tours, a social enterprise started by two students from Trinity College Dublin. The idea for the tour company came about when co-founder Tom Austin went to Vienna in April 2018 and took the Austrian capital’s top-rated visitor experience.

When he came back, Tom discovered there was nothing similar here. These tours exist all over Europe — in London, Prague, Barcelona — and he approached me about setting one up in Dublin.

Pierce jumped on board immediately. The pair then approached the Dublin Simon Community with their idea and found them to be “very supportive right from the off”. Things ran quickly and with a little help from the Trinity Launch Box fund for entrepreneurs, Secret Street Tours were ready by early October.

All that was missing was someone with a knowledge of Dublin and experience of being homeless.

“I was working on a part-time basis with the Dublin Simon Community,” says Derek.

“Tom came in to pitch the idea for Secret Street Tours and it caught my attention straight away. We arranged a follow-up meeting and it’s taken legs and grown. I’m the only guide at the moment.”

Derek was a mortgage holder when a relationship breakdown led to the repossession of his house in 2014. On the day he found himself homeless, he made his way out to Dublin Airport.

“I had a big suitcase with me,” recalls the 52-year-old. “I lived there for the best part of three weeks. I could blend in there, I could wash, nobody would look twice at me. I spent that time gathering my thoughts and figuring out how I was going to cope.

“The prospect of heading into the city centre terrified me, but it was a terror that I had to encounter at some point.” Having spent some time on the streets of Dublin, he now has a two-year contract to “get back on his feet”.

He lives in shared accommodation back in the Liberties where he was born, raised, and through which he now leads us on his tour. As we move away from the back of Dublin Castle and past windows that were smashed by suffragette Hanna Sheehy Skeffington, we move closer to Derek’s world.

It is no accident that we spend quite a bit of time around the Iveagh Buildings. Derek has an affinity with the area. He learnt to swim at the old Iveagh Baths, and was looked after at the Iveagh Childcare facilities. He tells us how negotiations between street traders and the Iveagh Trust resulted in the Iveagh Market and how many people were quite happy at the time to see stall owners move indoors.

Most striking is his memory of men queueing outside the Iveagh Hostel when he was a youth.

“Back then they were old people,” he says.

And most of them would have had issues with alcohol. What’s striking about today is that most of the people you see queueing up to get inside are young.

The message is clear. But this is no sermon. Derek points out that on our short 1.3km route there are no fewer than five homeless facilities and not everyone in the area is happy about their share of the social contract.

As we move between the grounds of St Patrick’s Cathedral and onto the Harry Potteresque Marsh’s Library, Derek explains what Secret Street Tours means to him.

“First and foremost it gave me a voice,” he says.

“It gave me a purpose and it connects me back into the city and its social issues.” Secret Street Tours is looking to bring in a new guide in this year and in time hopes to bring more into the company.

“It’s not just about giving tours,” says Derek. “I have been paired up with a mentor recently who is going to help me on my journey out of homelessness and so it’s a support network too. We need to make sure people coming out of homelessness are supported in their welfare and well-being, and that’s what this company is all about I think.”

Secret Street Tours run several 90-minute walking tours a week at €10 per person. To book your spot online, visit secretstreettours.org/